Spirocyclopropane isoxazolidines, octahydropyrindin-4-ones and beta-lactams with biomimetic ethylene release from the electrophilic substitution of a1,1-ethyleneallylzinc complex

Electrophilic substitution of 1-ethenylcyclopropyl mesylate by 3,3-diethoxy propanal in the presence of palladium(0) (5%) and diethylzinc (2 equivalent s) provided 5-cyclopropylidene-1,1-diethoxy-3-hydroxypentane its nitrone de rivatives underwent intramolecular cycloaddition to provide spirocyclopropa ne isoxazolidines. which then were transformed under thermal or acidic cond itions, into octahydropyrindin-4-ones or bicyclic beta -lactams with the et hylene phytohormone extrusion, respectively. Use of chiral auxiliaries, i.e , (L)-2-acetoxylactate can lead to enantiomerically enriched heterocycles.